Appraisal of acute and chronic arsenic exposure in differently exposed school children with special reference to micronuclei formation in urine epithelial cells: A comparative study in West Bengal, India

Abstract

Arsenic (As) contaminated dietary intake in daily routine can bring serious health hazards even in children. Considering drinking water ingestion and rice-grain consumption pattern, the daily dietary intake rate of As through drinking water for the exposed children was observed as 17.5 μg/kg bw/day, greater than apparently control group of children (0.2 μg/kg bw/day). Biological samples such as urine, hair and nail for the exposed children showed higher accumulation of As (159 μg/l, 3320 μg/kg and 4460 μg/kg) compared to controlled children (1.92 μg/l, 195 μg/kg and 331 μg/kg). Arsenic toxicity can eventually lead to future cancer risk which is sub-clinically manifested through biological samples along with formation of micronuclei in urine epithelial cells of the affected children. Notably, according to unpaired t-test, the detected numbers of micronuclei were significantly higher in the urine epithelial cells of exposed school children (3.25/1000 epithelial cells) compared to the control children (0.52/1000 epithelial cells). ‘Severity Adjusted Margin of Exposure’ (SAMOE) value also corresponds to the huge amount of risk (class 5) through drinking water consumption. Rice-grain samples from households and mid-day meal samples also fall under the category of Class 4 in exposed area during the risk thermometer study. The average future cancer risk to the school children from the exposed area was found to be 1 × 10−3, 0.4 × 10−3, and 1.4 × 10−3, whilst the control group belongs to an apparently lower cancer risk zone such as 0.016 × 10−3, 0.4 × 10−3, and 0.012 × 10−3 during the intake of domestic tube-well water, rice-grain and school tube-well water, respectively. Simultaneously, non-cancer risk from drinking water is much lower in control children; however, rice-grain poses similar amount of risk for both groups (0.3–2.2). Hence, corrective measures are required for the management of contaminated water along with cooking malpractices.